#include "apue.h"
#include <sys/wait.h>

int main(void) {
    long b= (long)NULL == 0L;
    printf("b is %ld.\n", b);
    printf("NULL equal (void *)0 is %d.\n", NULL == (void *)0);
    printf("NULL equal (char *)0 is %d.\n", NULL == (char *)0);


    if ((char *)0) {
        printf("(char *)0 is true\n");
    } else {
        printf("(char *)0 is false\n");
    }

    return 0;
}
